Format Numbers, Dates and Durations in Collabora Online Calc

Format amounts, rates, dates and long durations while checking that their underlying numeric meanings remain intact. Currency formatting does not convert exchange rates, and an ordinary time-of-day display can hide whole days.

Before you start: version and deployment gate

Collabora Online Calc in an English desktop browser using the compact menu interface; documentary baseline is co-25.04 branch snapshot 3847fbcfe35a234544cf163ed9e004a3d197337c. Actual deployed build, dialogs, save behavior and native screenshots remain unverified.

This is a documentation-supported practice and acceptance recipe, not a report of a successful native run. Record the server build from Help → About, the storage host, browser and interface before proceeding. The pinned Online menu source and English command labels establish the compact-menu entry points below; they do not prove that every host exposes them or that the server implements every dialog field. Online’s compact menu is still a browser interface, not Collabora Office Classic. Do not substitute desktop instructions when a control is absent.

Use a new private, disposable ODS workbook that you are permitted to edit. Opening or creating it is a storage-host operation: this guide cannot name a universal Nextcloud, ownCloud or other host button. Do not practice in a shared production file. If you cannot identify the host file and edit permissions, stop. Finish each cell entry with Enter before invoking another operation.

Create the numeric fixture

Use an English (USA) number-format locale for the expected displays below, if that choice is available in your deployed Format Cells dialog. Record the actual choice. Enter these cells individually so dates are constructed rather than guessed from an ambiguous string.

Cell	Input	Meaning
A1	Measure	Header
B1	Value	Header
A2	Amount	Label
B2	1234.5	Numeric amount
A3	Rate	Label
B3	0.075	Fraction equal to 7.5 percent
A4	Date	Label
B4	=DATE(2026;10;19)	19 October 2026
A5	Duration	Label
B5	=27/24	27 hours as a fraction of a day
D1	Tax	Label
D2	=B2*B3	Amount multiplied by rate
D3	=B5*24	Hours reconstructed from days

D2 should be 92.5875 before rounding for display, and D3 should be 27. If formula separators differ in your installation, use the documented local separator, not a text replacement of decimal punctuation. See formula separator troubleshooting.

Apply formats without altering input

1. Select B2 and choose Format → Cells…, established by the pinned Online menu and labels. The complete deployed Numbers tab is an unresolved UI check. Continue only if it exposes number category, decimals and locale/currency selection. Choose USD currency with two decimals; expect $1,234.50 in the stated locale. This is a label and rounding rule, not conversion of money.
2. Select B3, choose Percentage with one decimal, and expect 7.5%. Do not replace 0.075 with 7.5; that would produce 750 percent. The upstream Online currency-dropdown test separately checks USD/GBP display choices in the tabbed UI; it does not prove every Format Cells option.
3. Select B4 and choose an unambiguous year-month-day display. If a custom format-code field is present, use YYYY-MM-DD and verify 2026-10-19; otherwise select an equivalent offered pattern. Do not assume an exact format-code field exists until inspected.
4. Select B5. A custom elapsed-hour format such as [HH]:MM must be verified in the actual dialog and server. If accepted, the expected display is 27:00. A time-of-day pattern HH:MM can show 03:00, losing the visible whole day even though the numeric value is still 1.125. If elapsed formatting is unavailable, leave B5 numeric and use D3, explicitly labeled hours, rather than reporting a successful elapsed-time format.
5. Format D2 with two decimal places: its displayed value should be 92.59, while the formula remains =B2*B3. Inspect B2, B3 and the formulas through the formula/input line. Formatting is not a request to round the stored inputs.

Change and extend the example

Change B2 to 2000 and B3 to 0.08. Expect $2,000.00, 8.0%, and D2 equal to 160.00 under the chosen formats. Replace B5 with =49/24; D3 becomes 49, and an accepted elapsed format should show 49:00. The ordinary time-of-day alternative would show 01:00; keep that comparison in a separate copy only.

Add A6 as Next date, B6 as =B4+1, A7 as Next amount and B7 as 12.5. Apply the same date display to B6 and currency display to B7 explicitly. Expect 2026-10-20 and $12.50. Do not infer inherited formats from neighboring cells. In D4 enter =B4=DATE(2026;10;19) and D5 =B6-B4; expect TRUE and 1. Those formula checks avoid depending on a particular date serial origin.

Troubleshooting and final ledger

Hashes or clipped displays can mean the column is too narrow; widen B before changing values. A currency symbol from a different locale is not evidence that the amount was converted. If the date is text, rebuild it with DATE. Check whether decimals were typed with the expected locale separator and whether an apostrophe forced text. Final values are amount 2000, rate 0.08, tax 160, duration 49 hours, next date one day later and next amount 12.5. Record which optional custom-format controls were actually available; unresolved ones remain acceptance holds.

Save the completed result and check it again

Before the final save, choose or confirm the workbook filename Number-formats-final.ods using a host-supported naming operation, or record the actual existing ODS filename if renaming is unavailable. Record that filename, its authorized host folder/location and stable file identity or URL locally; keep access tokens private. A filename alone does not identify a unique file. Commit the last cell edit. Use File → Save if your host exposes it, then wait for the host/editor’s acknowledged save state. Save can be hidden by the integration; an icon changing or a completed download alone does not establish persistence. Close only after acknowledgement, reopen the exact recorded host object from that location. Verify its filename and stable identity, then compare the stated final ledger before creating any reset copy. Record the observed values and any warning. A failed reopen check is a failed acceptance test.

Keep this completed workbook unchanged. For optional resets or alternate cases, make a separately named copy using a host-supported copy operation, confirm its independent identity, and re-enter the exact starting fixture there. Do not rely on Undo after reopening. This walkthrough has not been executed in Online; expected results, source inspection and independent arithmetic do not certify UI behavior or file preservation. No native screenshot is included because none was captured for this fixture.